In order to cut the abovementioned materials a suitable cutting disc is used, for example a diamond cutting disc which necessarily must be provided with a suitable protection device in order to: prevent the operator from coming into contact with the rotating cutting disc and therefore suffering possible injury; prevent any diamond segments which may come off the cutting disc from being projected outside the working area, creating unsafe conditions for the operators; and contain the cutting fluid so that it is not sprayed also outside the working area and conveyed on the cutting disc itself.
For this purpose protection cowls or cases are provided, these covering the non-operative part of the disc, i.e. the part of the disc not in contact with the material to be cut and therefore substantially the top half of the disc.
Moreover, when it is required to cut a slab so as to obtain tiles, strips or any other semi-finished article for interior or urban furnishing, it is required to perform a series of longitudinal, transverse or oblique cuts which can not be performed directly after carrying out the first series of cuts; the parts being machined must be first spaced apart in order to be able to perform the subsequent cuts without damaging the adjacent parts.
This strip spacing operation may be performed manually, but must be performed by the operator, with the result that the machining time is increased considerably, and is also the cause of frequent positioning or alignment errors when performing the cuts. Moreover, the costs of the final product is increased in view of the high unit cost of specialized labour.
In order to reduce the cost and speed up the machining operation it has been thought to automate the manual operations described above by providing automatic manipulators.
There exist, therefore, machines with which manipulators for picking up and handling the pieces of cut material are associated.
For example, in the case of machines with a gantry structure, i.e. machines comprising two support structures which are arranged longitudinally and between which a spindle-carrying crossbeam extends transversely in a slidable manner, said crossbeam slidably supporting a sleeve support carriage on which in turn a spindle-carrying sleeve supporting on the bottom end a cutting spindle is vertically movable, it is possible to provide a second crossbeam which is similar to the spindle-carrying crossbeam and along which a sucker pick-up device slides. The manipulator has, in addition to the crossbeam with the pick-up device, a carriage which travels along the crossbeam on which the actual sucker pick-up device travels vertically.
Alternatively, the sucker manipulator may be mounted directly on the sleeve support carriage. In this case, the manipulator has a structure which extends from the spindle carrying sleeve and which is movable vertically with respect to the sleeve at the bottom end of which the sucker pick-up device is fixed.
According to another solution the sucker pick-up device extends from the cutting head in an external position and is provided with actuator means for moving it in the vertical direction.
Finally, according to another solution, the pick-up device is again mounted on the cutting head in a vertically stowed-away position, folded up against the head, and, if necessary, may be unfolded so as to be operative.
It is evident that all these automated solutions have various drawbacks.
Firstly it is required to provide manipulators with structures which are somewhat complex and are therefore costly.
Furthermore, these manipulators, owing to the various movable mechanical parts, are prone to faults or malfunctions. It is evident that a fault prevents execution of the cutting operations with consequent serious economic loss.
Furthermore these structures increase the overall dimensions of the machine and its final cost.